Refactor Qiniu upload integration and remove legacy handlers

- Replaced common upload handler and service with Qiniu-specific implementations in main.go and route registration.
- Deleted outdated upload_handler.go and qiniu_service.go files to streamline the codebase.
- Updated route definitions to utilize the new Qiniu upload handler for improved file upload management.

internal/routes/routes.go

@@ -7,7 +7,7 @@ import (
 	"gorm.io/gorm"
 
 	authhandler "wx_service/internal/common/auth/handler"
-	commonhandler "wx_service/internal/common/handler"
+	qiniuhandler "wx_service/internal/common/qiniu/handler"
 	"wx_service/internal/middleware"
 	rmhandler "wx_service/internal/remove_watermark/handler"
 	smokehandler "wx_service/internal/smoke/handler"
@@ -19,7 +19,7 @@ func Register(
 	authHandler *authhandler.AuthHandler,
 	videoHandler *rmhandler.VideoHandler,
 	smokeHandler *smokehandler.SmokeHandler,
-	uploadHandler *commonhandler.UploadHandler,
+	uploadHandler *qiniuhandler.UploadHandler,
 ) {
 	// Register 用来集中注册所有 HTTP 路由，便于工程结构更清晰：
 	// - main 只负责初始化（配置/DB/依赖注入）